Low cost adjustable RF resonator devices manufactured from conductive loaded resin-based materials

ABSTRACT

Inductor-capacitor (LC) RF resonator circuits are formed of a conductive loaded resin-based material. The conductive loaded resin-based material comprises micron conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers in a base resin host. The ratio of the weight of the conductive powder(s), conductive fiber(s), or a combination of conductive powder and conductive fibers to the weight of the base resin host is between about 0.20 and 0.40. The micron conductive powders are formed from non-metals, such as carbon, graphite, that may also be metallic plated, or the like, or from metals such as stainless steel, nickel, copper, silver, that may also be metallic plated, or the like, or from a combination of non-metal, plated, or in combination with, metal powders. The micron conductor fibers preferably are of nickel plated carbon fiber, stainless steel fiber, copper fiber, silver fiber, or the like. The conductive loaded resin-based inductor-capacitor (LC) RF resonator circuits can be formed using methods such as injection molding compression molding or extrusion. The conductive loaded resin-based material used to form the inductor-capacitor (LC) RF resonator circuits can also be in the form of a thin flexible woven fabric that can readily be cut to the desired shape.

[0001] This Patent Application claims priority to the U.S. ProvisionalPatent Application 60/464,236, filed on Apr. 21, 2003, and to the U.S.Provisional Patent Application 60/484,398, filed on Jul. 2, 2003, whichare herein incorporated by reference in their entirety.

[0002] This Patent Application is a Continuation-in-Part ofINT01-002CIP, filed as U.S. patent application Ser. No. 10/309,429,filed on Dec. 4, 2002, also incorporated by reference in its entirety,which is a Continuation-in-Part application of docket number INT01-002,filed as U.S. patent application Ser. No. 10/075,778, filed on Feb. 14,2002, which claimed priority to US Provisional Patent Applicationsserial No. 60/317,808, filed on Sep. 7, 2001, serial No. 60/269,414,filed on Feb. 16, 2001, and serial No. 60/317,808, filed on Feb. 15,2001.

BACKGROUND OF THE INVENTION

[0003] (1) Field of the Invention

[0004] This invention relates to resonator devices and, moreparticularly, to inductor-capacitor (LC), adjustable RF resonatordevices molded of conductive loaded resin-based materials comprisingmicron conductive powders, micron conductive fibers, or a combinationthereof, homogenized within a base resin when molded. This manufacturingprocess yields a conductive part or material usable within the EMF orelectronic spectrum(s).

[0005] (2) Description of the Prior Art

[0006] Resonator circuits are widely used in the art of electrical andelectronic systems. Resonator circuits are specialized forms ofoscillator circuits. An oscillator circuit swings between two modes, orstates, on a periodic basis. Typical electrical oscillators swingbetween upper and lower voltage states in either a sinusoidal or asquare wave fashion. Electrical oscillators are used in radiocommunications circuits for generating carrier waves or for tuning instations. Many circuits use oscillator circuits for system clocks, videorastering, and the like.

[0007] One important method for generating an oscillating signal is theinductor-capacitor (LC) oscillator circuit. In a LC oscillator circuit,energy is stored temporarily in either the inductor or the capacitor.During each phase of oscillation, energy is transferred from thecapacitor to the inductor or visa versa. The LC circuit oscillates atthe resonance frequency specified by the combined reactance of the LCnetwork. LC oscillators may combine active devices to provide energy ofoscillation as well as to compensate for resistance loss.

[0008] A particular form of a LC oscillator circuit is the RF resonatorcircuit. The RF resonator circuit can be adjusted, or tuned, to aparticular frequency during normal operation. RF resonator circuitsformed from LC oscillators are typically tuned by altering the value ofthe inductor and/or the capacitor to thereby select the resonantfrequency. This type of RF resonator circuit may be attached to anantenna that captures electromagnetic energy to thereby create a firststage of a RF receiver. Alternatively, the RF resonator circuit maycontrol an amplifier to thereby drive a RF carrier signal onto atransmitting antenna. The ability of the RF resonator circuit to tune orto select a particular frequency of oscillation allows a singletransmitter and/or receiver to broadcast and/or to receive RF signals ofvarying frequency. The LC resonator circuits in the art are typicallyfabricated using discrete capacitor and/or inductor components. Thesecomponents require tooling and add assembly complexity. Alternatively,LC oscillator circuits have been integrated onto integrated circuits.

[0009] Several prior art inventions relate to resonator and/oroscillator circuits, inductors, capacitors, and the integration thereof.U.S. Pat. No. 6,111,343 to Unami et al teaches a piezoelectric resonatordevice including conductive resin film to reduce contact capacitance.U.S. Pat. No. 4,267,480 to Kanematsu et al teaches a piezoelectricresonator device. U.S. Pat. No. 4,786,837 to Kalnin et al teaches acomposite ceramic/polymer sheet electrode transducer. U.S. Pat. No.6,664,863 B1 to Okamoto et al teaches a LC oscillator integrated onto anIC. U.S. Pat. No. 6,268,778 B1 to Mucke et al teaches a voltagecontrolled oscillator using a LC resonator with tunable frequency basedon a variable capacitor network. Cleland et al, in the article,“Fabrication of high frequency nanometer scale mechanical resonatorsfrom bulk Si crystal,” Applied Physics Letter 69(18), 28 Oct. 1996, pp.2653-55, teaches a crystal resonator on bulk Si.

SUMMARY OF THE INVENTION

[0010] A principal object of the present invention is to provide aneffective RF resonator circuit device.

[0011] A further object of the present invention is to provide a methodto form a RF resonator circuit device.

[0012] A further object of the present invention is to provide inductorsand/or capacitors for RF resonator circuit devices molded of conductiveloaded resin-based materials.

[0013] A yet further object of the present invention is to provideinductors and/or capacitors for RF resonator circuit devices molded ofconductive loaded resin-based material where the oscillator devicecharacteristics can be altered or the visual characteristics can bealtered by forming a metal layer over the conductive loaded resin-basedmaterial.

[0014] A yet further object of the present invention is to providemethods to fabricate adjustable inductors and/or capacitors for RFresonator circuit devices from a conductive loaded resin-based materialincorporating various forms of the material.

[0015] A yet further object of the present invention is to provide amethod to fabricate inductors and/or capacitors for RF resonator circuitdevices from a conductive loaded resin-based material where the materialis in the form of a fabric.

[0016] A yet further object of the present invention is to provide animproved inductor device by improving the characteristics of the corematerial.

[0017] A yet further object of the present invention is to provide amethod to replace discrete capacitors and/or inductors for RF resonatordevices with capacitors and/or inductors molded into a circuit.

[0018] In accordance with the objects of this invention, a LC tunableresonator device is achieved. The device comprises a capacitorcomprising a first plate comprising conductive loaded, resin-basedmaterial comprising conductive materials in a base resin host. A secondplate is fixably held nearby but not contacting the first plate suchthat the first plate and the second plate are capacitively coupled. Aninductor comprises a loop of the conductive loaded, resin-basedmaterial. At least one of the capacitor and the inductor has a varyingvalue.

[0019] Also in accordance with the objects of this invention, a LCtunable resonator device is achieved. The device comprises a capacitor.The capacitor comprises a first plate and a second plate. The firstplate comprises a conductive loaded, resin-based material comprisingconductive materials in a base resin host. A second plate is fixablyheld nearby but not contacting the first plate such that the first plateand the second plate are capacitively coupled. An inductor comprises aloop of the conductive loaded, resin-based material. At least one of thecapacitor and said inductor has a varying value. An antenna is coupledto the capacitor and the inductor.

[0020] Also in accordance with the objects of this invention, a methodto form a LC resonator device is achieved. The method comprisesproviding a conductive loaded, resin-based material comprisingconductive materials in a resin-based host. The conductive loaded,resin-based material is molded into the device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In the accompanying drawings forming a material part of thisdescription, there is shown:

[0022]FIGS. 1a and 1 b illustrate a first preferred embodiment of thepresent invention showing an inductor-capacitor (LC) RF resonatorcircuit with inductor and/or capacitor comprising a conductive loadedresin-based material. In FIG. 1a, an adjustable inductor is used fortuning. In FIG. 1b, an adjustable capacitor is used for tuning.

[0023]FIG. 2 illustrates a first preferred embodiment of a conductiveloaded resin-based material wherein the conductive materials comprise apowder.

[0024]FIG. 3 illustrates a second preferred embodiment of a conductiveloaded resin-based material wherein the conductive materials comprisemicron conductive fibers.

[0025]FIG. 4 illustrates a third preferred embodiment of a conductiveloaded resin-based material wherein the conductive materials compriseboth conductive powder and micron conductive fibers.

[0026]FIGS. 5a and 5 b illustrate a fourth preferred embodiment whereinconductive fabric-like materials are formed from the conductive loadedresin-based material.

[0027]FIGS. 6a and 6 b illustrate, in simplified schematic form, aninjection molding apparatus and an extrusion molding apparatus that maybe used to mold capacitors and/or inductors for LC oscillator circuitsof a conductive loaded resin-based material.

[0028]FIG. 7 illustrates a second preferred embodiment of the presentinvention further showing a capacitor device for a LC RF resonatorcircuit comprising plates of conductive loaded resin-based material.

[0029]FIG. 8 illustrates a third preferred embodiment of the presentinvention further showing an inductor device for a LC RF resonatorcircuit with a core comprising conductive loaded resin-based material.

[0030]FIG. 9 illustrates a fourth preferred embodiment of the presentinvention further showing a capacitor device for a LC RF resonatorcircuit comprising a multiple layer stack of plates of conductive loadedresin-based material.

[0031]FIG. 10 illustrates a fifth preferred embodiment of the presentinvention further showing an inductor device for a LC RF resonatorcircuit comprising a wound conductor of conductive loaded resin-basedmaterial.

[0032]FIG. 11 illustrates a sixth preferred embodiment of the presentinvention further showing an inductor device for a LC RF resonatorcircuit comprising a spiral wind of conductive loaded resin-basedmaterial.

[0033]FIG. 12 illustrates a seventh preferred embodiment of the presentinvention further showing an adjustable inductor device for a LC RFresonator circuit with a movable relationship between the winding andthe core.

[0034]FIG. 13 illustrates an eighth preferred embodiment of the presentinvention further showing an adjustable spiral inductor device for a LCRF resonator circuit with selectable tap points.

[0035]FIGS. 14a through 14 c, illustrate a ninth preferred embodiment ofthe present invention showing an adjustable capacitor device for a LC RFresonator circuit with a movable relationship between the capacitorplates.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] This invention relates to inductor-capacitor (LC) RF resonatorcircuits molded of conductive loaded resin-based materials comprisingmicron conductive powders, micron conductive fibers, or a combinationthereof, homogenized within a base resin when molded.

[0037] The conductive loaded resin-based materials of the invention arebase resins loaded with conductive materials, which then makes any baseresin a conductor rather than an insulator. The resins provide thestructural integrity to the molded part. The micron conductive fibers,micron conductive powders, or a combination thereof, are homogenizedwithin the resin during the molding process, providing the electricalcontinuity.

[0038] The conductive loaded resin-based materials can be molded,extruded or the like to provide almost any desired shape or size. Themolded conductive loaded resin-based materials can also be cut, stamped,or vacuumed formed from an injection molded or extruded sheet or barstock, over-molded, laminated, milled or the like to provide the desiredshape and size. The thermal or electrical conductivity characteristicsof inductor-capacitor (LC) RF resonator circuits fabricated usingconductive loaded resin-based materials depend on the composition of theconductive loaded resin-based materials, of which the loading or dopingparameters can be adjusted, to aid in achieving the desired structural,electrical or other physical characteristics of the material. Theselected materials used to fabricate the inductor-capacitor (LC) RFresonator circuit circuits are homogenized together using moldingtechniques and or methods such as injection molding, over-molding,thermo-set, protrusion, extrusion or the like. Characteristics relatedto 2D, 3D, 4D, and 5D designs, molding and electrical characteristics,include the physical and electrical advantages that can be achievedduring the molding process of the actual parts and the polymer physicsassociated within the conductive networks within the molded part(s) orformed material(s).

[0039] The use of conductive loaded resin-based materials in thefabrication of inductor-capacitor (LC) RF resonator circuitssignificantly lowers the cost of materials and the design andmanufacturing processes used to hold ease of close tolerances, byforming these materials into desired shapes and sizes. Theinductor-capacitor (LC) RF resonator circuits can be manufactured intoinfinite shapes and sizes using conventional forming methods such asinjection molding, over-molding, or extrusion or the like. Theconductive loaded resin-based materials, when molded, typically but notexclusively produce a desirable usable range of resistivity from betweenabout 5 and 25 ohms per square, but other resistivities can be achievedby varying the doping parameters and/or resin selection(s).

[0040] The conductive loaded resin-based materials comprise micronconductive powders, micron conductive fibers, or in any combinationthereof, which are homogenized together within the base resin, duringthe molding process, yielding an easy to produce low cost, electricallyconductive, close tolerance manufactured part or circuit. The micronconductive powders can be of carbons, graphites, amines or the like,and/or of metal powders such as nickel, copper, silver, or plated or thelike. The use of carbons or other forms of powders such as graphite(s)etc. can create additional low level electron exchange and, when used incombination with micron conductive fibers, creates a micron fillerelement within the micron conductive network of fiber(s) producingfurther electrical conductivity as well as acting as a lubricant for themolding equipment. The micron conductive fibers can be nickel platedcarbon fiber, stainless steel fiber, copper fiber, silver fiber, or thelike, or combinations thereof. The structural material is a materialsuch as any polymer resin. Structural material can be, here given asexamples and not as an exhaustive list, polymer resins produced by GEPLASTICS, Pittsfield, Mass., a range of other plastics produced by GEPLASTICS, Pittsfield, Mass., a range of other plastics produced by othermanufacturers, silicones produced by GE SILICONES, Waterford, N.Y., orother flexible resin-based rubber compounds produced by othermanufacturers.

[0041] The resin-based structural material loaded with micron conductivepowders, micron conductive fibers, or in combination thereof can bemolded, using conventional molding methods such as injection molding orover-molding, or extrusion to create desired shapes and sizes. Themolded conductive loaded resin-based materials can also be stamped, cutor milled as desired to form create the desired shape form factor(s) ofthe heat sinks. The doping composition and directionality associatedwith the micron conductors within the loaded base resins can affect theelectrical and structural characteristics of the inductor-capacitor (LC)RF resonator circuits and can be precisely controlled by mold designs,gating and or protrusion design(s) and or during the molding processitself. In addition, the resin base can be selected to obtain thedesired thermal characteristics such as very high melting point orspecific thermal conductivity.

[0042] A resin-based sandwich laminate could also be fabricated withrandom or continuous webbed micron stainless steel fibers or otherconductive fibers, forming a cloth like material. The webbed conductivefiber can be laminated or the like to materials such as Teflon,Polyesters, or any resin-based flexible or solid material(s), which whendiscretely designed in fiber content(s), orientation(s) and shape(s),will produce a very highly conductive flexible cloth-like material. Sucha cloth-like material could also be used in forming inductor-capacitor(LC) oscillator circuits that could be embedded in a person's clothingas well as other resin materials such as rubber(s) or plastic(s). Whenusing conductive fibers as a webbed conductor as part of a laminate orcloth-like material, the fibers may have diameters of between about 3and 12 microns, typically between about 8 and 12 microns or in the rangeof about 10 microns, with length(s) that can be seamless or overlapping.

[0043] The conductive loaded resin-based material of the presentinvention can be made resistant to corrosion and/or metal electrolysisby selecting micron conductive fiber and/or micron conductive powder andbase resin that are resistant to corrosion and/or metal electrolysis.For example, if a corrosion/electrolysis resistant base resin iscombined with stainless steel fiber and carbon fiber/powder, then acorrosion and/or metal electrolysis resistant conductive loadedresin-based material is achieved. Another additional and importantfeature of the present invention is that the conductive loadedresin-based material of the present invention may be made flameretardant. Selection of a flame-retardant (FR) base resin materialallows the resulting product to exhibit flame retardant capability. Thisis especially important in inductor-capacitor (LC) oscillator circuitsapplications as described herein.

[0044] The homogeneous mixing of micron conductive fiber and/or micronconductive powder and base resin described in the present invention mayalso be described as doping. That is, the homogeneous mixing convertsthe typically non-conductive base resin material into a conductivematerial. This process is analogous to the doping process whereby asemiconductor material, such as silicon, can be converted into aconductive material through the introduction of donor/acceptor ions asis well known in the art of semiconductor devices. Therefore, thepresent invention uses the term doping to mean converting a typicallynon-conductive base resin material into a conductive material throughthe homogeneous mixing of micron conductive fiber and/or micronconductive powder into a base resin.

[0045] As an additional and important feature of the present invention,the molded conductor loaded resin-based material exhibits excellentthermal dissipation characteristics. Therefore, inductor-capacitor (LC)RF resonator circuits manufactured from the molded conductor loadedresin-based material can provide added thermal dissipation capabilitiesto the application. For example, heat can be dissipated from electricaldevices physically and/or electrically connected to aninductor-capacitor (LC) RF resonator circuit of the present invention.

[0046] Referring now to FIGS. 1a and 1 b, a first preferred embodimentof the present invention is illustrated. An inductor-capacitor (LC) RFresonator circuit 10 is shown. The LC RF resonator circuit 10, ornetwork, comprises parallel connected inductor L 14 and capacitor 16. Inthis configuration, energy is coupled into the circuit 10 from anantenna 12. This energy will begin to oscillate between temporarystorage in the inductor L 14 and in the capacitor C 16 as it dischargesto ground 18. For example, as electrostatic field energy begins todischarge from the capacitor C 14, current flows through the inductor L16 to thereby create a magnetic field. Once the capacitor C 14completely discharges, the back EMF of the inductor L 16 attempts tomaintain the current flow and thereby begins to charge the capacitor C14 in the opposite polarity as at the beginning of the cycle. Theinductor L 16 magnetic field completely collapses just as the capacitorC 14 is recharged to the opposite polarity. At this point, the cyclebegins with current flow in the opposite direction.

[0047] The LC RF resonator circuit 10 will accept energy of anyfrequency. However, energy at the resonant frequency (f_(o)) issustained more easily in the LC circuit 10 than energy at otherfrequencies. This resonant frequency is given by:

f _(o)=1/2π(LC)½

[0048] Energy at this resonant frequency f_(o) will be captured moreefficiently (with less loss) by the resonator 10. In the presentinvention, the inductor L 16 and/or the capacitor C 14 comprise aconductive loaded resin-based material according to the presentinvention. Further, the inductor L 16 is a variable value inductor. Byvarying the value of the inductor L 16, the resonance frequency f_(o) ofthe RF resonant circuit 10 can be selected according to the aboveequation. In this way, the RF resonator circuit 10 can be tuned to aparticular frequency of electromagnetic energy. This function isparticularly useful for application of the RF resonance circuit 10 toreception of multiple frequency signals such as in a radio receiver.

[0049] Referring now to FIG. 1b, the RF resonance circuit 20 mayalternatively comprise a variable capacitor 24 and a fixed inductor 26between the antenna 22 and ground 28. By varying the value of thecapacitor 24, the resonance frequency f_(o) of the RF resonant circuit20 may again be selected according to the above equation. Alternatively,a RF resonance circuit where both the capacitance value and the inductorvalue are variable may be realized using capacitor and/or inductordevices according to the present invention.

[0050] In the present invention, the inductor L 26 and/or the capacitorC 24 comprise a conductive loaded resin-based material according to thepresent invention. The use of the conductive loaded resin-material toform capacitor plates and/or inductor cores and/or inductor windingsencompasses several important features as discussed below and as shownin the preferred embodiments of FIGS. 7 through 11. In addition, inFIGS. 12, 13, and 14 a through 14 c, several preferred embodiments ofvariable inductor and capacitor devices are shown. It is particularlyimportant to note that the capacitor or the inductor or both thecapacitor and the inductor may comprise the conductive loadedresin-based material. The inductor or capacitor may be formed separatelyand assembled together. Alternatively, the inductor or capacitor may beformed together using, for example, a molding operation. It is furtherunderstood that multiple capacitor or multiple inductor circuits orcircuits with different configurations of inductor and capacitor deviceswhere either the capacitor or the inductor or both the capacitor and theinductor comprise the conductive loaded resin-based material are withinthe scope of the present invention. Finally, the antenna 22 mayadditionally comprise the conductive loaded resin-based materialaccording to the invention. In this regard, the entire RF resonatorcircuit 20 may be molded of the conductive loaded resin-based materialaccording to the present invention.

[0051] Referring now particularly to FIG. 7, a second preferredembodiment of the present invention is illustrated. In this embodiment,a capacitor device, or capacitor enhanced circuit section, 100 for theLC circuit of the present invention is formed of conductive loadedresin-based material according to the present invention. Moreparticularly, the capacitor 100 comprises plates 102 and 106 ofconductive loaded resin-based material where the plates are separated bya dielectric layer 104. In the preferred case, the dielectric layer 104comprises a resin-based material and, more preferably, comprises thesame base resin as is used in the plates 102 and 1066. The capacitor 100is preferably a molded device and is more preferably molded onto or intoa circuit where the conductive loaded resin-based material provideselectrical connection.

[0052] For example, the lower plate 106 or terminal (T2) of thecapacitor 100 is injection molded of conductive loaded resin-basedmaterial. Next, the dielectric layer 104, comprising the same base resinmaterial but without the conductive loading, is over-molded onto thelower plate 106. Finally, the upper plate 102 or terminal (T1) isover-molded onto the dielectric layer 104. Preferably, the upper andlower plates 102 and 106 comprise the same composition of conductiveloaded resin-based material but this is not essential to the presentinvention. Alternatively, the dielectric layer 104 may be any type ofinsulator exhibiting a dielectric constant value in the needed range forthe particular capacitor. For example, a layer of ceramic, mica,polyester, or paper may be used as the dielectric layer 104.Alternatively, the top and bottom plates 102 and 106 may be separatedonly by air 104. In this case, the air 104 is the used as thedielectric. The dielectric layer 104 may be applied by over-molding,extrusion, spraying, dipping, coating, or insertion (as in the case ofpaper). Conversely, the upper and lower plates 102 and 106 may beover-molded onto a previously formed dielectric layer 104. For example,a thin layer of ceramic 104 may first be formed. Then, upper and lowerplates of conductive loaded resin-based material 102 and 106 may beover-molded onto the ceramic dielectric 104. Alternatively, upper andlower plates 102 and 106 may be extruded over a pre-formed dielectriclayer 104. The plates 102 and 106 may be formed as a continuous piece ofconductive loaded resin-based material surrounding a dielectric layer104 and then trimmed, cut, stamped, milled, or the like, to electricallyseparate the upper and lower plates 102 and 106 and to complete thecapacitor.

[0053] Referring now to FIG. 8, a third preferred embodiment of thepresent invention is illustrated. An inductor 120 for the LC circuit ofthe present invention is illustrated. In this case, the core 126comprises the conductive loaded resin-based material 122 with aninsulating layer 124 overlying. A metal wire 128 is formed around thecore 126 as the conductor. Alternatively, the conductor 128 may compriseconductive loaded resin-based material as is discussed below. Theexcellent permeability of the conductive loaded resin-based material 122is featured. In particular, a molded conductive loaded resin-based core122 can easily be made if a conductive loading material with a highpermeability is chosen. For example, conductive loading materials with ahigh iron content are particularly useful in forming a high permeabilitycore 122. In the preferred embodiment, the core comprises a conductiveloaded resin based center 122 surrounded by an insulating layer 124.More preferably, the center core 122 is first molded of conductiveloaded resin-based material using injection molding or extrusion, andthen the insulating layer 124 is over-molded, coated, or extruded overthe center core 122. Finally, a metal wire conductor 128 is wound aroundthe core 122 to complete the inductor 120. Alternatively, the conductor128 may comprise yet more conductive loaded resin-based material that isover-molded onto the core 126.

[0054] This inductor device 120 allows a large inductance value to begenerated through the use the high permeability core material 122. Themoldability of the conductive loaded resin-based material of the core122 allows for more flexible manufacturing methods and for integrationof the inductor into a conductive loaded resin-based circuit design. Inaddition, the conductive loaded resin-based core will exhibit corrosionand/or electrolysis resistance. Further, by adjusting the doping leveland/or of the type of conductive material in the conductive loadedresin-based material, the permeability and the resistivity of the core122 can be easily optimized.

[0055] In particular, a molded conductive loaded resin-based core 122can easily be made if a conductive loading material with a highpermeability is chosen. For example, conductive loading materials with ahigh iron content are particularly useful in forming the highpermeability core 122. As a particular example, an austinetic stainlesssteel fiber or powder is particularly useful since this type ofstainless steel alloy has a relatively high iron content. In addition,the permeability of the base resin material is an importantconsideration. Preferably, a base resin material of relatively highpermeability is used for the core.

[0056] Referring now to FIG. 9, a fourth preferred embodiment 140 of thepresent invention is illustrated. In this embodiment, a stackedcapacitor device 140, or capacitor enhanced circuit section, for the LCcircuit of the present invention is formed of conductive loadedresin-based material according to the present invention. In this case,the middle layer 146 of the stack 140 is one capacitor plate or terminal(T2), while the upper most and lower most layers of conductive loadedresin-based material 142 and 150 are connected together to form theother capacitor plate (T1). Dielectric layers 144 and 148 are used toseparate the capacitor plates 142, 146, and 150. Molding techniques,such as calendaring, that are useful for forming sheets of resin-basedmaterial, may be used according to the present invention to form sheetsof conductive loaded resin-based material 142, 146, and 150, which canthen be stacked with intervening dielectric layers 144 and 148 to formlarge value capacitors. For example, the stack 140 may be bound togetherusing ultrasonic welding.

[0057] The conductive loaded resin-based capacitor plates 142, 146, and150 of the present invention allow the capacitor devices to be moldedinto a circuit or a circuit housing. Further, these plates can beformulated to exhibit excellent corrosion and/or electrolysis resistanceand/or moisture penetration resistance such that the resulting capacitorstructure can be used in environmentally challenging environments. Forexample, by selecting a corrosion resistant base resin and a corrosionresistant conductive load, such as stainless steel, the resultingcapacitor plates 142, 146, and 150, can be made corrosion resistant. Inaddition, the resistivity of the conductive loaded resin-based materialcan be easily optimized by altering the ratio of doping material tobase-resin material. In this way, a passive resistance value can bebuilt into the capacitor plates 142, 146, and 150. The ability to moldthe capacitor devices into the circuit or housing facilitates reducingthe number of discrete capacitor components in a circuit to therebyreduce part count, tooling costs, and assembly complexity. As yetanother alternative, the inner plate 146 may comprise any conductivematerial including a metallic material. In this case, a dielectric layer144 and 148 may be coated onto the metal inner plate 146. Then aconductive loaded resin based material 142 and 150 is simply over-moldedonto the metal inner plates 146 with a dielectric coating 144 and 148therebetween to form the capacitor 140.

[0058] Referring now to FIG. 10, a fifth preferred embodiment of thepresent invention is illustrated. An inductor 160 for the LC circuit ofthe present invention is illustrated. A conductive loaded resin-basedconductor 168 is formed around a core 162. A core material is notessential to this embodiment. However, if used, a core 162 can increasethe inductor value and/or provide electrical isolation and/or mechanicalstability to the inductor 160. The core material 162 may comprise any ofseveral materials. For example, the core 162 may simply comprise aninsulating material of relatively low permeability. In this case, thecore 162 may simply provide mechanical stability and electricalisolation. For example, a resin-based material may be first molded toform a core 162. Then the conductor 168 of conductive loaded resin-basedmaterial is over-molded onto the core 162. In this case, the core 162may be hollow (air core) or may be solid. Alternatively, if theconductive loaded resin-based material is first formed into afabric-like material, then this material 168 may be wound onto the core162.

[0059] Alternatively, a conductive core 164 may be used. As is discussedabove, the permeability of the core material will determine how much thecore affects the inductance. For example, iron is well known as a corematerial with a high permeability. In the preferred embodiment shown,the core comprises a metal inner layer 164 with a surrounding insulatinglayer 166. In this arrangement, the insulating layer 166 may be appliedto a previously formed metal core 164. Then the coil conductor 168 ofconductive loaded resin-based material is over-molded onto the core 162.The resulting inductor 160 exhibits a higher inductance value due to thepresence of the metal core 164.

[0060] The conductive loaded resin-based coil 168 may be used to form aninductor 160 of high inductance. In addition, by selecting theconductive material doping level of the conductive loaded resin-basedmaterial 168, the resistance of the inductor 10 can be carefullycontrolled. For example, by selecting a higher ratio of conductivematerial to base resin, a low resistivity conductive loaded resin-basedmaterial 168 is formed. Alternatively, by using a lower ratio ofconductive material to base resin, a high resistivity conductive loadedresin-based material 168 is formed. In this way, the parasiticresistance of the inductor 160 can be carefully designed.

[0061] Referring now to FIG. 11, a sixth preferred embodiment of thepresent invention is illustrated. A spiral inductor device 180 for theLC oscillator circuit of the present invention is illustrated. Thespiral inductor 180 again comprises the conductive loaded resin-basedmaterial of the present invention. The spiral pattern forms parallelsignal lines for current to flow from a first terminal 190 to a secondterminal 194 or visa versa. A bridge section 186 connects over or underthe spiral lines 184 to connect the second terminal 194 to the internaltermination of the inductor 180. The spiral inductor 180 will generatemagnetic field perpendicular to the plane of the inductor 180. Thisinductor device 180 is easily formed by injection molding, over-molding,and the like. Alternatively, a flexible conductive loaded resin-basedmaterial 184 may be extrusion molded and then formed into the spiralshape.

[0062] The various inductor and capacitor embodiments of the presentinvention may be integrated together to provide oscillator circuits withL and C functions. These functions can be easily molded into a circuitor housing to thereby save part count, tooling cost, and assemblycomplexity. The performance and/or visual characteristics of thecapacitor and/or the inductor devices can be altered by forming a metallayer over the conductive loaded resin-based material. If this metallayer is used and if the method of formation is metal plating, then theresin-based structural material of the conductive loaded, resin-basedmaterial is one that can be metal plated. There are very many of thepolymer resins that can be plated with metal layers. For example, GEPlastics, SUPEC, VALOX, ULTEM, CYCOLAC, UGIKRAL, STYRON, CYCOLOY are afew resin-based materials that can be metal plated. The metal layer maybe formed by, for example, electroplating or physical vapor deposition.

[0063] Referring now to FIG. 12, a seventh preferred embodiment of thepresent invention is illustrated. An adjustable inductor device 200 fora LC RF resonator circuit is shown. The adjustable inductor device 200comprises a core 204 and a winding 208 with a movable relationship. Thatis, the core 204 can be moved into or out of the winding 208 to create avariable amount of winding overlap with the core 204. The value of theinductor between the terminations of the winding 208 will vary accordingto the relative amount of core 204 insertion into the hollow of thewinding 208. In this embodiment, the core 204 may comprise theconductive loaded resin-based material, the winding 208 may comprise theconductive loaded resin-based material, or both the core 204 and thewinding 208 may comprise the conductive loaded resin-based material.

[0064] Referring now to FIG. 13, an eighth preferred embodiment of thepresent invention is illustrated. In this embodiment, an adjustablespiral inductor device 220 for a LC RF resonator circuit is illustrated.The spiral inductor 220 again comprises the conductive loadedresin-based material of the present invention. The spiral pattern formsparallel signal lines 222 for current to flow from a first terminal 224to any one of the second terminals 228, 232, 236, or 240, or visa versa.Bridge sections 244 connects over or under the spiral lines 222 toconnect the second terminals 228, 232, 236, and 240 terminal 194 tointernal terminations of the inductor 220 at various lengths. Forexample, a connection to the topmost second terminal 228 will create aspiral current path with four winds and with the largest inductivevalue. If the connection is moved to the next terminal 232 down, thenthe spiral current path with three winds and with the next largestinductive value is selected, and so on. A switching circuit, not shown,can easily be made to select between each terminal. The variable spiralinductor 220 will generate magnetic field perpendicular to the plane ofthe inductor 220. This variable inductor device 220 is easily formed byinjection molding, over-molding, and the like. Alternatively, a flexibleconductive loaded resin-based material 222 may be extrusion molded andthen formed into the spiral shape.

[0065] Referring now to FIGS. 14a through 14 c, a ninth preferredembodiment of the present invention is illustrated. An adjustablecapacitor device 260 for a LC RF resonator circuit is shown. Theadjustable capacitor device 260 comprises first and second plates 268and 272 of the conductive loaded resin-based material. The plates 272and 268 are held near one another, though not touching, to therebycreate significant capacitive coupling. Further, a movable relationshipis created between the capacitor plates 268 and 272 such that theoverlap between the plates can be varied. In the embodiment shown, a pin264 is used to maintain a fixed separation between the plates 268 and272 as shown in the cross section of FIG. 14b. The top view isillustrated in FIG. 14a showing a minimal overlap area 280 between theplates. In this position, the variable capacitor 14 c exhibits a minimalcapacitance value. In FIG. 14c, one plate 268 is rotated around thepivot pin 264 such that the overlap area 280 between the platessubstantially increases. As a result, the capacitance value increases.The variable capacitor device 260 may be fabricated, for example, bymolding the top and bottom plates 268 and 272 of conductive loadedresin-based material and then assembling these plates onto an insulatingpin 264.

[0066] The conductive loaded resin-based material typically comprises amicron powder(s) of conductor particles and/or in combination of micronfiber(s) homogenized within a base resin host. FIG. 2 shows crosssection view of an example of conductor loaded resin-based material 32having powder of conductor particles 34 in a base resin host 30. In thisexample the diameter D of the conductor particles 34 in the powder isbetween about 3 and 12 microns.

[0067]FIG. 3 shows a cross section view of an example of conductorloaded resin-based material 36 having conductor fibers 38 in a baseresin host 30. The conductor fibers 38 have a diameter of between about3 and 12 microns, typically in the range of 10 microns or between about8 and 12 microns, and a length of between about 2 and 14 millimeters.The conductors used for these conductor particles 34 or conductor fibers38 can be stainless steel, nickel, copper, silver, or other suitablemetals or conductive fibers, or combinations thereof. These conductorparticles and or fibers are homogenized within a base resin. Aspreviously mentioned, the conductive loaded resin-based materials have aresistivity between about 5 and 25 ohms per square, other resistivitiescan be achieved by varying the doping parameters and/or resin selection.To realize this resistivity the ratio of the weight of the conductormaterial, in this example the conductor particles 34 or conductor fibers38, to the weight of the base resin host 30 is between about 0.20 and0.40, and is preferably about 0.30. Stainless Steel Fiber of 8-11 micronin diameter and lengths of 4-6 mm with a fiber weight to base resinweight ratio of 0.30 will produce a very highly conductive parameter,efficient within any EMF spectrum. Referring now to FIG. 4, anotherpreferred embodiment of the present invention is illustrated where theconductive materials comprise a combination of both conductive powders34 and micron conductive fibers 38 homogenized together within the resinbase 30 during a molding process.

[0068] Referring now to FIGS. 5a and 5 b, a preferred composition of theconductive loaded, resin-based material is illustrated. The conductiveloaded resin-based material can be formed into fibers or textiles thatare then woven or webbed into a conductive fabric. The conductive loadedresin-based material is formed in strands that can be woven as shown.FIG. 5a shows a conductive fabric 42 where the fibers are woven togetherin a two-dimensional weave 46 and 50 of fibers or textiles. FIG. 5bshows a conductive fabric 42′ where the fibers are formed in a webbedarrangement. In the webbed arrangement, one or more continuous strandsof the conductive fiber are nested in a random fashion. The resultingconductive fabrics or textiles 42, see FIG. 5a, and 42′, see FIG. 5b,can be made very thin, thick, rigid, flexible or in solid form(s).

[0069] Similarly, a conductive, but cloth-like, material can be formedusing woven or webbed micron stainless steel fibers, or other micronconductive fibers. These woven or webbed conductive cloths could also besandwich laminated to one or more layers of materials such asPolyester(s), Teflon(s), Kevlar(s) or any other desired resin-basedmaterial(s). This conductive fabric may then be cut into desired shapesand sizes.

[0070] Inductor-capacitor (LC) oscillator circuits formed fromconductive loaded resin-based materials can be formed or molded in anumber of different ways including injection molding, extrusion orchemically induced molding or forming. FIG. 6a shows a simplifiedschematic diagram of an injection mold showing a lower portion 54 andupper portion 58 of the mold 50. Conductive loaded blended resin-basedmaterial is injected into the mold cavity 64 through an injectionopening 60 and then the homogenized conductive material cures by thermalreaction. The upper portion 58 and lower portion 54 of the mold are thenseparated or parted and the inductor-capacitor (LC) oscillator circuitsare removed.

[0071]FIG. 6b shows a simplified schematic diagram of an extruder 70 forforming inductor-capacitor (LC) oscillator circuits using extrusion.Conductive loaded resin-based material(s) is placed in the hopper 80 ofthe extrusion unit 74. A piston, screw, press or other means 78 is thenused to force the thermally molten or a chemically induced curingconductive loaded resin-based material through an extrusion opening 82which shapes the thermally molten curing or chemically induced curedconductive loaded resin-based material to the desired shape. Theconductive loaded resin-based material is then fully cured by chemicalreaction or thermal reaction to a hardened or pliable state and is readyfor use.

[0072] The advantages of the present invention may now be summarized. Aneffective oscillator circuit device and method of manufacture isachieved. Inductors and/or capacitors for oscillator circuit devices aremolded of conductive loaded resin-based materials. The oscillator devicecharacteristics can be altered or the visual characteristics can bealtered by forming a metal layer over the conductive loaded resin-basedmaterial. Methods to fabricate inductors and/or capacitors foroscillator circuit devices from a conductive loaded resin-based materialincorporate various forms of the material. An improved inductor deviceis achieved by improving the characteristics of the core material. Amethod to replace discrete capacitors and/or inductors for oscillatordevices with capacitors and/or inductors molded into a circuit isachieved.

[0073] As shown in the preferred embodiments, the novel methods anddevices of the present invention provide an effective and manufacturablealternative to the prior art.

[0074] While the invention has been particularly shown and describedwith reference to the preferred embodiments thereof, it will beunderstood by those skilled in the art that various changes in form anddetails may be made without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A LC tunable resonator device comprising: acapacitor comprising: a first plate comprising a conductive loaded,resin-based material comprising conductive materials in a base resinhost; and a second plate fixably held nearby but not contacting saidfirst plate such that said first plate and said second plate arecapacitively coupled; and an inductor comprising a loop of saidconductive loaded, resin-based material wherein at least one of saidcapacitor and said inductor have a varying value.
 2. The deviceaccording to claim 1 wherein the ratio, by weight, of said conductivematerials to said resin host is between about 0.20 and about 0.40. 3.The device according to claim 1 wherein said conductive materialscomprise metal powder.
 4. The device according to claim 3 wherein saidmetal powder is nickel, copper, or silver.
 5. The device according toclaim 3 wherein said metal powder is a non-conductive material with ametal plating.
 6. The device according to claim 5 wherein said metalplating is nickel, copper, silver, or alloys thereof.
 7. The deviceaccording to claim 3 wherein said metal powder comprises a diameter ofbetween about 3 μm and about 12 μm.
 8. The device according to claim 1wherein said conductive materials comprise non-metal powder.
 9. Thedevice according to claim 8 wherein said non-metal powder is carbon,graphite, or an amine-based material.
 10. The device according to claim1 wherein said conductive materials comprise a combination of metalpowder and non-metal powder.
 11. The device according to claim 1 whereinsaid conductive materials comprise micron conductive fiber.
 12. Thedevice according to claim 11 wherein said micron conductive fiber isnickel plated carbon fiber, stainless steel fiber, copper fiber, silverfiber or combinations thereof.
 13. The device according to claim 11wherein said micron conductive fiber has a diameter of between about 3μm and about 12 μm and a length of between about 2 mm and about 14 mm.14. The device according to claim 1 wherein said conductive materialscomprise a combination of conductive powder and conductive fiber. 15.The device according to claim 1 further comprising an antenna coupled tosaid capacitor and said inductor.
 16. The device according to claim 1wherein said capacitor is variable and wherein said first plate and saidsecond plate are movably related such that an overlap area of said firstplate and said second plate can be varied.
 17. The device according toclaim 16 wherein said second plate comprises metal.
 18. The deviceaccording to claim 16 wherein said second plate comprises saidconductive loaded resin-based material.
 19. The device according toclaim 16 wherein said first plate and said second plate comprisemultiple material planes that are interlaced to increase parallelsurfaces therebetween.
 20. The device according to claim 16 wherein oneof said first and second plates further comprises a circuit trace on amolded circuit board.
 21. The device according to claim 16 wherein oneof said first and second plates further comprises a part of a moldedhousing for an electrical device.
 22. The device according to claim 1wherein said inductor is variable and further comprises a core structurelocated inside said loop wherein said core structure alters theinductance of said loop and wherein said core structure and said loopare held in a movable relationship.
 23. The device according to claim 22further comprising an electrically insulating layer surrounding saidloop.
 24. The device according to claim 23 wherein said electricallyinsulating layer is a resin-based material.
 25. The device according toclaim 22 wherein said core structure comprises conductive loadedresin-based material.
 26. The device according to claim 22 wherein saidconductive loaded resin-based material comprises an iron-basedconductive load.
 27. The device according to claim 22 wherein said corestructure comprises a metal.
 28. The device according to claim 22wherein said loop comprises multiple turns of said conductive loadedresin-based material.
 29. The device according to claim 1 wherein saidinductor is variable and further comprises multiple terminalscorresponding to multiple inductance values for said inductor based onselection of said multiple terminals.
 30. A LC tunable resonator devicecomprising: a capacitor comprising: a first plate comprising aconductive loaded, resin-based material comprising conductive materialsin a base resin host; and a second plate fixably held nearby but notcontacting said first plate such that said first plate and said secondplate are capacitively coupled; an inductor comprising a loop of saidconductive loaded, resin-based material wherein at least one of saidcapacitor and said inductor have a varying value; and an antenna coupledto said capacitor and said inductor.
 31. The device according to claim30 wherein the ratio, by weight, of said conductive materials to saidresin host is between about 0.20 and about 0.40.
 32. The deviceaccording to claim 30 wherein said conductive materials comprise metalpowder.
 33. The device according to claim 33 wherein said metal powderis a non-conductive material with a metal plating.
 34. The deviceaccording to claim 30 wherein said conductive materials comprisenon-metal powder.
 35. The device according to claim 30 wherein saidconductive materials comprise a combination of metal powder andnon-metal powder.
 36. The device according to claim 30 wherein saidconductive materials comprise micron conductive fiber.
 37. The deviceaccording to claim 30 wherein said conductive materials comprise acombination of conductive powder and conductive fiber.
 38. The deviceaccording to claim 30 wherein said capacitor is variable and whereinsaid first plate and said second plate are movably related such that anoverlap area of said first plate and said second plate can be varied.39. The device according to claim 38 wherein said second plate comprisesmetal.
 40. The device according to claim 38 wherein said second platecomprises said conductive loaded resin-based material.
 41. The deviceaccording to claim 38 wherein said first plate and said second platecomprise multiple material planes that are interlaced to increaseparallel surfaces therebetween.
 42. The device according to claim 38wherein one of said first and second plates further comprises a circuittrace on a molded circuit board.
 43. The device according to claim 38wherein one of said first and second plates further comprises a part ofa molded housing for an electrical device.
 44. The device according toclaim 30 wherein said inductor is variable and further comprises a corestructure located inside said loop wherein said core structure altersthe inductance of said loop and wherein said core structure and saidloop are held in a movable relationship.
 45. The device according toclaim 44 further comprising an electrically insulating layer surroundingsaid loop.
 46. The device according to claim 45 wherein saidelectrically insulating layer is a resin-based material.
 47. The deviceaccording to claim 44 wherein said core structure comprises conductiveloaded resin-based material.
 48. The device according to claim 44wherein said conductive loaded resin-based material comprises aniron-based conductive load.
 49. The device according to claim 44 whereinsaid core structure comprises a metal.
 50. The device according to claim44 wherein said loop comprises multiple turns of said conductive loadedresin-based material.
 51. The device according to claim 30 wherein saidinductor is variable and further comprises multiple terminalscorresponding to multiple inductance values for said inductor based onselection of said multiple terminals.
 52. A method to form a LCresonator device, said method comprising: providing a conductive loaded,resin-based material comprising conductive materials in a resin-basedhost; and molding said conductive loaded, resin-based material into saiddevice.
 53. The method according to claim 52 wherein the ratio, byweight, of said conductive materials to said resin host is between about0.20 and about 0.40.
 54. The method according to claim 52 wherein theconductive materials comprise a conductive powder.
 55. The methodaccording to claim 52 wherein said conductive materials comprise amicron conductive fiber.
 56. The method according to claim 52 whereinsaid conductive materials comprise a combination of conductive powderand conductive fiber.
 57. The method according to claim 52 wherein saidmolding comprises: injecting said conductive loaded, resin-basedmaterial into a mold; curing said conductive loaded, resin-basedmaterial; and removing said device from said mold.
 58. The methodaccording to claim 57 further comprising forming a dielectric layer oversaid device.
 59. The method according to claim 58 wherein said step offorming a dielectric layer comprises over-molding.
 60. The methodaccording to claim 58 wherein said step of forming a dielectric layercomprises dipping, spraying, or coating.
 61. The method according toclaim 57 further comprising forming a dielectric layer prior to saidstep of injecting said conductive loaded, resin-based material into amold wherein said device is over-molded onto said dielectric layer. 62.The method according to claim 52 wherein said molding comprises: loadingsaid conductive loaded, resin-based material into a chamber; extrudingsaid conductive loaded, resin-based material out of said chamber througha shaping outlet; and curing said conductive loaded, resin-basedmaterial to form said device.
 63. The method according to claim 62further comprising stamping or milling said molded conductive loaded,resin-based material.
 64. The method according to claim 62 furthercomprising forming a dielectric layer over said device.
 65. The methodaccording to claim 64 wherein said step of forming a dielectric layercomprises extrusion.
 66. The method according to claim 62 wherein saidstep of forming a dielectric layer comprises dipping, spraying, orcoating.